Fuel injection system



Dec. 19, 1961 M. E. NOFTZ ET AL 3,013,545

FUEL INJECTION SYSTEM Filed June 1, 1959 5 Sheets-Sheet l INVENTORJ %a7'/ 2,? A a/2 2. 5502672 2. 67414771,

Dec. 19, 1961 Filed June 1, 1959 M. E. NoFTz ETAL FUEL INJECTION SYSTEM 5 Sheets-Sheet 2 Dec. 19, 1961 M. E. NOFTZ ET AL FUEL INJECTION SYSTEM Filed June 1, 1959 5 Sheets-Sheet 3 INVENTOR-$'. year] I Nofz z. figZeri 76rw$a7rz United States Patent 3,013,545 FUEL INJECTION SYSTEM Mearl E. Noftz, Birmingham, and Robert P. Graham, Pontiac, Mich, assignors to Chrysler Corporation, Highland Park, Mich, a corporation of Delaware Filed June 1, 1959, Ser. No. 817,383 18 Claims. (Cl. 123-119) This invention relates to a fuel injection system particularly suited for use in an automotive internal combustion engine.

An object of the present invention is to provide an improved fuel injection system of the above type wherein pressurized fuel from a fuel pump is supplied by a fuel feed conduit to the engine through fuel metering means operable in response to variations in engine speed and load. A pressure regulating valve in the fuel conduit and responsive to the pressure thereof at opposite sides of the fuel metering means maintains a comparatively high predetermined minimum pressure differential across the latter to minimize vapor formation therein and to assure its reliable operation regardless of variations in fuel pressure resulting from changes in speed, load, inertial effects, vehicle inclination, and the like. In consequence, the tolerances for the fuel pump as well as for the dimensions of the conduit system can be relaxed materially with resulting cost savings and without affecting critical pressure relation across the metering means.

Another object is to provide such a fuel injection system including an accelerator pump which can be linked with the customary accelerator pedal and personally operated to inject a burst of pressurized fuel into the feed conduit at a location downstream of the metering means for accelerating the engine, and to provide an operable connection between the accelerator pump and the pressure metering means to augment operation of the latter to increase the fuel flow to the engine.

In a type of fuel injection system with which the present invention is particularly adapted, the metering means includes a housing partitioned by a movable wall into a first fuel pressure chamber and a second or fuel pressure balancing chamber. The first chamber comprises part of the feed conduit and has an orifice therein associated with valve means adjustable to restrict the orifice and thereby to control the fuel flow to the engine. The movable wall is operably connected with the valve means and with a sensor device responsive to an engine operating condition and is shiftable to adjust the valve means in accordance with the balance of forces effected by the sensor device and the pressure differential between the two chambers. A pressure equalizing duct in communication with the pressure balancing chamber and the feed conduit at a location downstream of the metering means maintains the same pressure differential between the first chamber and said downstream location that exists across the movable wall. In the event of sudden opening of the engine throttle for the purpose of increasing the fuel supply to the engine with such a system, a sudden outflow of fuel from the first chamber results in a momentary change in the forces on the movable wall causing the latter to move in a direction to decrease the volume of the first chamber and to increase the volume of the second chamber. In consequence, without provision to the contrary, fuel is robbed from the feed conduit via the equalizing duct in order to fill the increased volume of the second chamber. This causes momentary leanness of the fuel-air mixture during acceleration.

Other objects of the invention are accordingly to provide simple improved means for preventing such an occurrence and in particular to provide a fluid connection between the pressurized fuel of the accelerator pump and the second or pressure balancing chamber to prevent robhing of fuel from the feed conduit during sudden acceleration of the engine; to provide a one-way check valve in said fluid connection to prevent a reverse fluid flow toward the accelerator pump when the latter is not supplying pressurized fuel to said movable portion; and to provide resilient means normally holding the check valve closed and being yieldable to open the check valve for passage of fluid in said fluid connection when the accelerator pump pressure exceeds a predetermined minimum.

Another object is to provide such a structure wherein said pressure regulating valve is applied to vary the restriction in said feed conduit at a point downstream of the aforesaid location associated with said pressure equalizing duct.

Other objects are to provide a branch of said fluid connection opening into said feed conduit at a location downstream of said pressure regulating valve means; and to provide a one-way check valve in said branch to prevent a reverse fuel flow from said feed conduit to said accelerator pump, the check valve means being yieldably urged to a closed position and being responsive to the accelerator pump output pressure to open when the latter pressure exceeds a predetermined minimum value.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

FIGURE 1 is a fragmentary schematic sectional view of a fuel injection system embodying the present invention.

FIGURE 2 is a view similar to FIGURE 1, showing a modified form of the invention.

FIGURE 3 is a view similar to FIGURE 1, showing still another modification of the invention.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to FIGURE 1, a fuel injection system is shown comprising separate cylinder banks 10, air intake manifold conduits 11, exhaust manifold conduits 12, and exhaust manifolds 13. The system comprises a fuel supply tank 14-, an engine operated speed sensor 15, an engine load sensor 16, an accelerator pump 17, and fuel injection nozzles 18. The speed sensor is provided with four housing portions 19, 20, 21, and 22 separated from each other by diaphragms 23, 24, and 25 to provide four chambers 26, 27, 28, and 29. Chamber 26 communi cates with fuel tank 14- through conduit 30 and by means of fuel pump 31 submerged in tank 14 is supplied with fuel in adequate volume and pressure to exceed the maximum requirements of the engine regardless of the engine load or speed. A return flow metering orifice 32 in housing portion 19 connects chamber 26 with a return flow conduit 33 which extends to fuel tank 14 to return excess fuel thereto. A return flow metering valve 35 having a flattened end registering with the upstream side of orifice 32 is secured to each of the diaphragms 23, 24, and 25 by suitable grommets 36 and plates 36a.

A flyweight support 37 pivotally supports flyweights 38 at 34 and is secured to a flexible shaft 39 which is operatively connected to the engine to rotate at a speed directly proportional to engine speed. The flyweights 38 have projections 40' which abut an end portion of valve 35 when the flyweights pivot outwardly in response to rotation of shaft 39, thereby to urge valve 35 toward orifice 32 against the opposite force of the fuel pressure in chamber 26 applied to diaphragm 23. Thus as engine speed increases or decreases respectively, valve 35 is moved toward or away from metering orifice 32 to restrict or increase the latters opening.

Although the present invention is illustrated herein by way of example with a return flow type fuel injection system, it will be apparent from the following that the invention has application with other than return flow systems, as for example wherein orifice 32 is closed and valve 35 is applied to conduit 30 to restrict the fuel fiow therethrough with increasing pressure in chamber 26; or wherein conduit 30 is closed and the fuel is pumped in a reverse direction through conduit 33 into chamber 26 and valve 35 is applied to restrict orifice 32 with increasing pressure in chamber 26.

Chamber 26 is connected with a downstream chamber 40 via load metering orifice 41 and thence with a downstream fuel distribution chamber or rosette 42 via fuel supply conduits 43 and 44 in series. A load metering needle 45 extends through orifice 41 and terminates in a reversely tapered end portion 46 registering with the upstream side of orifice 41. Needle 45 is operatively connected to a piston 47 reciprocable in cylinder 48, which in turn is connected with a low pressure portion of each intake manifold 11 of said engine by conduit 49. Low pressure transmitted through conduit 49 causes piston 47 to move upwardly against the force of spring 50 and to urge the tapered valve 46 into closer proximity with the sides of orifice 41 to progressively restrict the latter. Conversely, with increasing pressure in the intake mani folds, as for example with increasing load, spring 50 urges piston 46 downwardly to increase the opening of orifice 41. Vent duct 48a in the lower portion of cylinder 48 maintains the space below piston 47 at atmospheric pressure.

A separate noz'zle feed conduit 51 extends from chamber 42 to each of the fuel injection nozzles 18 located downstream of the throttle valve 52 in the air intake manifold 53. Chamber 40 is also connected to chamber 27 of the speed sensor unit by a pressure equalizing con duit 54 to provide an adjustment of the fuel pressure differential across the metering orifice 41, as explained below.

An idle boost conduit 55 communicates with manifold 53 at a point adjacent the edge of throttle valve 52 and with the chamber 28 of the speed sensor unit in order to augment operation of the fiyweights 38 urging rightward movement of valve 35 when the engine is operated at low speed and light load. By virtue of duct 55, the pressure in chamber 28 during such conditions is lower than in chamber 29 which is vented to the atmosphere by vent 57. The pressure in chamber 29 thus urges valve 35 toward orifice 32 to retard the flow of return fuel therethrough and provide an enrichment of the engine fuel supply. During high speed or high load operation, the pressure differential across diaphragm 25 has no appreciable effect.

The accelerator pump 17 has an inlet duct 58 in communication with return flow conduit 33 via ball check valve 56 and receives fuel into the lower portion of cylinder 59 upon upward movement of the accelerator piston 60. In the present instance, piston 60 is connected in accordance with customary practice with the personally operated accelerator linkage 60a which is also suitably connected with throttle 52 as indicated schematically to open the latter conjointly with downward movement of piston 60. Depression of the accelerator piston 60 by operation of linkage 60a forces fuel from cylinder 59 into the engine to accelerate the latter as described below. Bleed duct 61 connects cylinder 59 above piston 60 with return conduit 33 to facilitate operation of piston 60 and to prevent entrapment of fuel in the upper portion of cylinder 59.

The acceleration fuel discharged from cylinder 59 upon downward movement of piston 60 is directed through conduit 62 to the upper chamber 63 of fluidcontaining pressure operated check valve housing 64 partitioned by a flexible diaphragm 65 into the aforesaid upper chamber 63 and a lower chamber 66. A shiftable needle valve element 67 secured to diaphragm 65 to move therewith has a tapered upper end registering with an acceleration orifice 68 to close the latter. Upon downward movement of valve element 67, orifice 68 communicates with chamber 27 via conduit 71. Needle valve 67 is normally maintained in the closed position shown by a biasing coil spring 69 under compression between the under side of diaphragm 65 and a lower portion of the housing 64. Chamber 66 is in communication with return flow conduit 33 via duct 70, whereby excess pressure buildup in chamber 66 is avoided and the return flow pressure in conduit 33 is employed to augment spring 69 in maintaining valve element 67 in the closed position.

When the accelerator piston 60 is depressed to discharge fuel from cylinder 59 in an accelerating operation, the acceleration fuel pressure directed to chamber 63 forces diaphragm 65 downwardly against the tension of spring 69, thereby causing valve element 67 to open orifice 68. Opening of the latter orifice admits the accelerating fuel to chamber 27 and thus exerts the accelerator pump pressure on diaphragm 23 urging the same to the right against the pressure in chamber 26 and tending to restrict orifice 32. The accelerating fuel is also supplied under the pressure of pump 17 to chamber 48 via duct 54 and thence to the engine via conduits 43, 44, and 51. The aforesaid restricting of orifice 32 during the period of acceleration reduces the return fuel flow in conduit 33 and facilitates the pressure rise in chamber 26 and maintain the desired pressure differential across orifice 41.

It is to be noted that upon opening of throttle 52 to accelerate the engine, the pressure in conduit 49 increases, enabling spring 50 to move valve 46 downward and decrease the restriction at orifice 41. In consequence, the pressure in chamber 26 tends to drop momentarily. Prior to the present invention wherein pressurized fuel from the accelerator pump is applied directly to chamber 27, the sudden pressure drop in chamber 26 would cause rightward movement of diaphragm 23 and a resulting low pressure in chamber 27. The latter in turn would rob fuel from chamber 40 via duct 54, momentarily reducing the fuel pressure in chamber 40. The fuel supply to the engine would thus be reduced at the very time that acceleration was desired and coughing or momentary stalling of the engine would result. By virtue of the connection between the discharge side of the accelerator pump 17 and chamber 27, diaphragm 23 is not prevented from rightward movement, but such movement does not result in a momentary pressure drop in chambers 27 and 40. Instead the pressures in these chambers is increased to augment the fuel supply via conduits 43 and 44 to give the engine a burst of acceleration fuel as desired. When the accelerator pump is not operating, spring 69 holds valve 67 at its upper closed position, preventing back flow of fuel through port 68 into chamber 63 and thereby maintaining the desired pressure relationships across the metering orifices 32 and 41.

The lower chamber 74 of a fluid containing pressure regulator or pressure increasing valve housing 75 is connected by duct 73 with the return flow conduit 33, the housing 75 being partitioned by a flexible diaphragm 76 to provide the aforesaid lower chamber 74 and an upper chamber 77. A needle valve element 78 secured to diaphragm 76 to move therewith extends upwardly to register with a metering orifice 79 which communicates with conduit 44 adjacent its juncture with conduit 43. A biasing spring 80 under compression between the under side of diaphragm 76 and a lower portion of housing 75 urges needle valve element 78 upwardly to maintain a predea A n termined minimum differential between the fuel pressure in conduit 43 and the fuel pressure in the return flow conduit 33, as described below.

As is apparent from FIGURE 1, the pressure in conduit 33 augments the force of spring 80 urging diaphragm 76 and needle valve 78 upwardly in opposition to the pressure in feed conduit 43 urging diaphragm 76 downwardly. Upward or downward movement respectively of valve element 78 progressively restricts or opens orifice 79. In the event of a pressure increase in conduit 33 for any cause, as for example on inclination of the vehicle to raise fuel tank 14 with respect to metering orifice 32, the pressure increase is transmitted to the under side of diaphragm 76 to increase the restriction of orifice 79 when the pressure in feed conduit 44 drops below a predetermined minimum value, as for example when the engine is operating at low load. The pressure in feed duct 43 is thereby increased to increase the pressure in chamber 27 via conduit 54 and also to increase the pressure in chamber 77 via duct 81 connected with feed conduit 43.

The increased pressure in chamber 27 urges diaphragm 23 to the right because of its larger area with respect to the area of diaphragm 24, causing valve 35 to increase the restriction of metering orifice 32. The latter action reduces the pressure in return conduit 33 and also in chamber 74. The resulting reduced upward force on diaphragm 76, augmented by the increased pressure in chamber 77, tends to restore the opening of orifice 79 to the extent predetermined by biasing spring 80. Accordingly, any tendency to increase the pressure in return conduit 33 results in a corresponding tendency to increase the pressure in chambers 26 and 40, so that the pressure diiferential between conduits 33 and 43 will not drop below a predetermined minimum value determined by the force of spring 86. This structure is particularly important during light engine loads when the pressure downstream of port 79 is a minimum. Valve 78 assures a comparatively high minimum pressure upstream of port 79 and minimizes the tendency of fuel vapor formation during such conditions in the metering system.

The operation of the speed sensor 15 and load sensor 16 will be described in relation to a static engine operating condition, that is constant engine speed and load. Under static conditions, the force exerted on valve 35 by flyweights 38 equals the force exerted on valve 35 by the fuel pressure differential across diaphragm 23, whereby valve 35 is positioned with respect to orifice 32 so as to maintain a pressure differential across orifice 41 determined by engine speed. In this static condition, the amount of fuel delivered to the rosette 42 is constant and is equal to the amount of fuel delivered to the system by the pump 31 less the amount of fuel being returned to the fuel tank 14 through the return flow conduit 33.

As throttle valve 52 is moved to a more open position by operation of the engine accelerator including linkage 60a, an increase in manifold pressure is transmitted to the load sensor piston 47 through conduit 49, enabling spring 50 to move piston 47 downwardly and thereby to move the load metering valve 46 to a more open position with respect to the metering orifice 41. The pressure differential existing across orifice 41 and therefore across diaphragm 23 consequently tends to decrease as more fuel is allowed to flow into chamber 40. To prevent such a condition and to maintain the pressure differential across orifice 41 at a value where the flow of fuel therethrough will satisfy the increased engine load requirement, the fuel pressure in chamber 26 is increased by movement of the return flow metering valve 35 closer to orifice 32 in consequence of the increased pressure in chamber 27 which communicates via duct 54 with chamber 40. Thus the return fuel flow in conduit 33 is decreased and the fuel flow to the engine via conduits 43 and 44 is increased. Similarly when the engine speed is increased, the flyweights 38 exert increased force on valve 35 urging the latter rightward to restrict orifice 32. The result is to decrease the return fuel flow in conduit 33 and increase the flow to the engine via conduits 43 and 44. The converse operation will of course occur in the event of a reduction in engine load or speed.

FIGURE 2 shows a modified formof the present invention wherein conduit 71 is connected directly with the discharge side of accelerator pump 17 at a location between port 68 and the underside of piston 60. In FIG- URE 2, conduit '71 is connected with chamber 63 upstream of valve 67. In addition, port 68 is connected directly with rosette chamber 42 by duct 82.

Upon operation of accelerator pump 17 to exert sufiicient fuel pressure in chamber 63 to overcome the tension of spring 69, a charge of accelerating fuel will be supplied to the feed conduit system 44 downstream of the pressure regulating valve 78. This latter action in addition and supplemental to the aforementioned pressurizing of chambers 27 and 40 by the pumping operation of accelerator pump 17 to prevent robbing of fuel from chamber 40 when the throttle valve 52 is opened and diaphragm 23 is moved to the right.

The structure of FIGURE 2 is advantageous because it is undesirable to supply too much pressure during acceleration to the back side of diaphragm 23, i.e., to chamber 27. Otherwise the excess pressure in chamber 27 will cause too great a restriction or orifice 32 and an unbalancing of the metering system which could result in flooding of the engine and Waste of fuel during acceleration. In FIGURE 1, this problem is met by suitably determining the size of the accelerator pump 17 and the resistance to fuel flow in lines 62 and 71. In FIGURE 2 on the other hand, greater versatility and control is enabled with relaxed production tolerances. The accelerating fuel pressure in excess of a desired value determined by spring 69 is supplied directly to the engine, so that undue unbalancing of the metering system, including the relationship of valve 35 and orifice 32 and the pressure drop across orifice 41, is avoided. In overall structure, FIGURE 2 is similar to FIGURE 1, so that corresponding parts are numbered the same.

FIGURE 3 shows a modified form of the present inven tion wherein valve 64 and conduit 62 are eliminated. Conduit 71 is connected directly with the accelerator cylinder 59 below piston 60. Otherwise, the operation and function of the parts are the same as described above in regard to FIGURE 1. Corresponding parts are numbered the same in both figures. The elimination of check valve 64 achieves a simplification and economy of structure and results in a structure which is reasonably serviceable in the manner of the FIGURE 1 structure. It is to be noted in regard to both FIGURES 2 and 3 that during deceleration of the engine and movement of throttle valve 52 toward its closed position shown, the accelerator pump piston 60 is raised for a fuel inlet stroke. Fuel then enters cylinder 59 both through duct 58 and check valve 56 and through conduit 71 from chamber 27. This latter effect reduces the pressure in chamber 27 and causes leftward movement of diaphragm 23 and opening of orifice 32. In consequence the fuel pressure in both chambers 26 and 40, as well as the fuel flow to the engine is reduced thereby to minimize unburned fuel in the engine exhaust system during rapid deceleration.

We claim:

1. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, adjustable fuel metering means associated with said fuel conduit means for regulating the fuel flow to said engine, acceleration fuel pumping means selectively operable to supply pressurized accelerating fuel to said engine, and means operably connecting said pumping means with said metering means to adjust the same to augment operation of the latter tending to increase the fuel flow to said engine.

2. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means comprising a shiftable valve element associated with said fuel conduit means for regulating the fuel flow to said engine, valve actuating means responsive to an operating condition of said engine for shifting said valve element, acceleration fuel pumping means selectively operable to supply pressurized accelerating fuel to said engine, and means operably connecting said pumping means with said valve element to augment operation of the latter tending to increase the fuel fiow to said engine.

3. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, fuel metering means comprising a shiftable valve element associated with said fuel conduit means for regulating the fuel fiow to said engine, valve actuating means responsive to an operating condition of said engine for shifting said valve element, a pressure actuated element operably connected with said valve element to move the same, acceleration fuel pumping means selectively operable to supply pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said pressure actuated element to augment operation of the latter tending to increase the fuel flow to said engine.

4. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, pressure actuated means operably connected with said valve means to adjust the latter, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said pressure actuated means to urge adjustment of said valve means tending to increase the fuel flow to said engine.

5. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, means responsive to an engine operating condition and operably connecting with said valve means for adjusting the latter, pressure actuated means operably connected with said valve means to adjust the latter, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said pressure actuated means to urge adjustment of said valve means tending to increase the fuel fiow to said engine.

6. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine.

7. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter to progressively decrease the fuel flow to said engine with increasing fuel pressure in said chamber, engine speed responsive means operably connected with said valve means and urging adjustment of the latter in opposition to the pressure in said chamber with increasing engine speed, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine.

8. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter to progressively decrease the fuel flow to said engine with increasing fuel pressure in said chamber, a second orifice in said conduit means, second adjustable valve means for selectively restricting said second orifice to control the fuel flow to said engine, engine speed responsive means operably connected with one of said valve means to adjust the same, engine load responsive means operably connected with the other of said valve means to adjust the same, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine.

9. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter to progressively decrease the fuel fiow to said engine with increasing fuel pressure in said chamber, a second orifice in said conduit means in series with said chamber downstream thereof, a pressure equalizing conduit connecting the fuel pressure of said conduit means at a location downstream of said second orifice with said movable portion to oppose the pressure in said chamber, second adjustable valve means for selectively restricting said second orifice to control the fuel flow to said engine, engine speed responsive means operably connected with one of said valve means to adjust the same, engine load responsive means operably connected with the other of said valve means to adjust the same, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine.

10. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter to progressively decrease the fuel flow to said engine with increasing fuel pressure in said chamber, a second orifice in said conduit means, second adjustable valve means for selectively restricting said second orifice to control the fuel flow to said engine, engine speed responsive means operably connected with the first-named valve means and urging adjustment of the latter in opposition to the pressure in said chamber with increasing engine speed, engine load responsive means operably connected with said second valve means and urging adjustment of the latter to increase the fuel flow to said engine with increasing engine load, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine.

11. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber having an orifice therein, adjustable valve means for selectively restricting said orifice to control the flow of fuel to said engine, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter to progressively decrease the fuel flow to said engine with increasing fuel pressure in said chamber, a second orifice in said conduit means in series with said chamber downstream thereof, a pressure equalizing conduit connecting the fuel pressure of said conduit means at a location downstream of said second orifice with said movable portion to oppose the pressure in said chamber, second adjustable valve means for selectively restricting said second orifice to control the fuel flow to said engine, engine speed responsive means operably con 'nected with the first-named valve means and urging adjustment of the latter in opposition to the pressure in said chamber with increasing engine speed, engine load responsive means operably connected with said second valve means and urging adjustment of the latter to increase the fuel flow to said engine with increasing engine load, acceleration fuel pumping means for supplying pressurized accelerating fuel to said engine, and duct means conmeeting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine.

12. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including an orifice opening into a fuel pressure chamber, fuel metering means responsive to engine speed and load for controlling the fuel flow to said engine including adjustable valve means associated with said orifice for selectively restricting the same, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means selectively operable for supplying pressurized accelerating fuel, duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine, and pressure equalizing duct means connecting said conduit means at a location downstream of said fuel metering means with said movable portion in opposition to the pressure in said chamber.

13. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including an orifice opening into a fuel pressure chamber, fuel metering means responsive to engine speed and load for controlling the fuel flow to said engine including adjustable valve means associated With said orifice for selectively restricting the same, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means selectively operable for supplying pressurized accelerating fuel, duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine, pressure equalizing duct means connecting said conduit means at a location downstream of said fuel metering means with said movable portion in opposition to the pressure in said chamber, and pressure regulating means connected with said conduit means, said pressure regulating means being responsive to the pressure in said conduit means at one point downstream of said location and at a second point spaced from said chamber by said orifice for maintaining a uniform pressure differential between said points.

14. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including an orifice opening into a fuel pressure chamber, fuel metering means responsive to engine speed and load for controlling the fuel flow to said engine including adjustable valve means associated with said orifice for selectively restricting the same, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means selectively operable for supplying pressurized accelerating fuel, duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine, one-Way check valve means in said duct means for blocking fuel flow from said chamber to said acceleration fuel pumping means, pressure equalizing duct means conmeeting said conduit means at a location downstream of said fuel metering means with said movable portion in opposition to the pressure in said chamber, and pressure regulating means connected with said conduit means, said pressure regulating means being responsive to the pressure in said conduit means at one point downstream of said location and at a second point spaced from said chamber by said orifice for maintaining a uniform pressure differential between said points.

15. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including an orifice opening into a fuel pressure chamber, fuel metering means responsive to eng ne speed and load for controlling the fuel flow to said engine including adjustable valve means associated with said orifice for selectively restricting the same, said chamher having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means selectively operable for supplying pressurized accelerating fuel, duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine, said duct means having a duct portion connected with said conduit means downstream of said metering means, one-way check valve means in said duct portion for blocking fuel flow from said conduit means to said acceleration fuel pumping means, pressure equalizing duct means connecting said conduit means at a location downstream of said fuel metering means with said movable portion in opposition to the pressure in said chamber, and pressure regulating means connected with said conduit means, said pressure regulating means being respons1ve to the pressure in said conduit means at one point downstream of said location and at a second point spaced from said chamber by said orifice for maintaining a uniform pressure differential between said points, both said location and said one point being upstream of the connection between said duct portion and conduit means.

16. In a fuel system for an internal combustion engine,

fuel conduit means for supplying said engine with fuel, said conduit means including an orifice opening into a fuel pressure chamber, fuel metering means responsive to engine speed and load for controlling the fuel flow to said engine including adjustable valve means associated with said orifice for selectively restricting the same, said cham her having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means selectively operable for supplying pressurized accelerating fuel, duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine, said duct means having a duct portion connected with said conduit means downstream of said metering means, one-way check valve means in said duct portion for blocking fuel flow from said conduit means to said acceleration fuel pumping, means yieldingly urging said check valve means to a position closing communication between said conduit means and pumping means, means responsive to the pressure of said accelerating fuel for opening communication between said conduit means and pumping means, pressure equalizing duct means connecting said conduit means at a location downstream of said fuel metering means with said movable portion in opposition to the pressure in said chamber, and pressure regulating means connected with said conduit means, said pressure regulating means being responsive to the pressure in said conduit means at one point downstream of said location and at a second point spaced from said chamber by said orifice for containing a uniform pressure difierential between said points, both said location and said one point being upstream of the connection between said duct portion and conduit means.

17. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber in communication with a fuel source, said chamber having a return fiow orifice opening thereinto for returning excess fuel to said source, fuel metering mean responsive to an operating condition of said engine for controlling the fuel fiow thereto including adjustable valve means associated with said orifice for selectively restricting the same, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means selectively operable for supplying pressurized accelerating fuel, duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said valve means tending to increase the fuel flow to said engine, pressure equalizing duct means connecting said conduit means at a location downstream of said fuel metering means with said movable portion in opposition to the pressure in said chamber, and pressure regulating means connected with said conduit means, said pressure regulating means being responsive to the pressure in said conduit means at one point downstream of said location and at a second point spaced from said chamber by said orifice for maintaining a uniform pressure differential between said points.

18. In a fuel system for an internal combustion engine, fuel conduit means for supplying said engine with fuel, said conduit means including a fuel pressure chamber in communication with a fuel source, said chamber having a return flow orifice opening thereinto for returning excess fuel to said source, fuel metering means responsive to an operating condition of said engine for controlling the fuel flow thereto including adjustable valve means associated with said orifice for selectively restricting the same, said chamber having a movable portion responsive to the pressure in said chamber and operably connected with said valve means to adjust the latter, acceleration fuel pumping means selectively operable for supplying pressurized accelerating fuel, duct means connecting the pressure of said accelerating fuel with said movable portion to oppose the pressure in said chamber and urge adjustment of said'valve means tending to increase the fuel flow to said engine, said duct means havig a duct portion connected with said conduit means downstream of said metering means, one-way check valve means in said duct portion for blocking fuel flow from said conduit means to said acceleration fuel pumping means, mean yieldingly urging said check valve means to a position closing communication between said conduit means and pumping means, means responsive to the pressure of said accelerating fuel for opening communication between said conduit means and pumping means, pressure equalizing duct means connecting said conduit means at a location downstream of said fuel metering means with said movable portion in opposition to the pressure in said chamber, and pressure regulating means connected with said conduit means, said pressure regulating means being responsive to the pressure in said conduit means at one point downstream of said location and at a second point spaced from said chamber by said orifice for maintaining a uniform pressure differential between said points, both said location and said one point being upstream of the connection between said duct portion and conduit means.

Greenland Mar. 30, 1948 Deschamps June 9, 1953 M r is...

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 013545 December 19 1961 "Mearl E. Neftz et-al-y It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read as "corrected below.

Column 11 line 26 for "containing" read maintaining si ned'afid sealed thi s 8th day of May 1962, i I

(SEAL) Attest:

ERNEST Wu VIDER v DAVID L. LADD Attesting Officer Commissioner of Patents 

